This disclosure relates to a medical device and more specifically to a neuro stimulator that produces an electrical stimulation signal used to influence the human body.
The medical device industry produces a wide variety of electronic and mechanical devices for treating patient medical conditions. Depending upon medical condition, medical devices can be surgically implanted or connected externally to the patient receiving treatment. Clinicians use medical devices alone or in combination with drug therapies and surgery to treat patient medical conditions. For some medical conditions, medical devices provide the best, and sometimes the only, therapy to restore an individual to a more healthful condition and a fuller life. One type of medical device that can be used is an Implantable Neuro Stimulator (INS)
An INS generates an electrical stimulation signal that is used to influence the human nervous system or organs. Electrical contacts carried on the distal end of a lead are placed at the desired stimulation site such as the spine and the proximal end of the lead is connected to the INS. The INS is then surgically implanted into an individual such as into a subcutaneous pocket in the abdomen, pectoral region, or upper buttocks area. The INS can be powered by an internal source such as a battery, or by an external source such as a radio frequency transmitter. A clinician programs the INS with a therapy using a programmer. The therapy configures parameters of the stimulation signal for the specific patient's therapy. An INS can be used to treat conditions such as pain, incontinence, movement disorders such as epilepsy and Parkinson's disease, and sleep apnea. Additional therapies appear promising to treat a variety of physiological, psychological, and emotional conditions. Before an INS is implanted to deliver a therapy, an external screener that replicates some or all of the INS functions is typically connected to the patient to evaluate the efficacy of the proposed therapy.
When a screener is used to test the efficacy of a stimulation therapy, the screener including its leads should be fully operational to correctly assess the efficacy of the proposed stimulation therapy. When previous screeners were operationally connected to a patient, the clinician would verify that the leads were operational. Once the patient left the clinician's office the stimulation therapy efficacy could be reduced by stimulation energy not reaching the targeted site due to leads that have become inoperative through a nonconformance, disconnection, or open connection, and the patient might not become aware of the inoperative lead until the next visit with a clinician. In other situations the leads may become temporarily inoperative which can subject the patient to abrupt initiation and cessation of stimulation therapy causing patient discomfort and unreliable indications of efficacy. Unreliable efficacy testing data can result in some patients not receiving an INS when the therapy would have treated their medical condition, and other patients receiving an INS when the therapy would not effectively treat their medical condition. An example of a screener is shown in a brochure titled “Model 3625 Screener” available from Medtronic, Inc., Minneapolis, Minn., and examples of some neuro stimulation products and related components are shown and described in a brochure titled “Implantable Neurostimulation Systems” also available from Medtronic, Inc.
For the foregoing reasons there is a need for a screener that can diagnose inoperative leads to improve operation in areas such as reliability, and patient comfort.